Comparison of Building Codes and Insulation in China and Iceland

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1 Prceedngs Wrld Gethermal Cngress 00 Bal, Indnesa, 5-9 prl 00 Cmparsn f Buldng Cdes and Insulatn n Chna and Iceland Hayan Le and Pall Valdmarssn Tanjn Gethermal esearch & Tranng Centre, Tanjn Unversty, Tanjn 0007, Chna Lehy6@yah.cm eywrds: Heat lad, Insulatn, Buldng cdes BSTCT Heat lad fr a sample buldng wth and wthut nsulatn usng Chnese and Icelandc buldng cdes was calculated n ths paper. The results shw that the calculated heat lad n Icelandc cdes s bgger than that f n Chnese fr the un-nsulated buldng. Hwever, when nsulatn s added t the buldng envelpe, heat lad decreases 5.% n Chnese cdes. If the thermal nsulatn prperty s mprved t satsfy the Icelandc standard, whch was vald at the tme f cnstructn fr the sample buldng, the heat lad decreases 70.%, whch ndcates that mprvng thermal nsulatn and nsulatn prpertes culd reduce energy cnsumptn sgnfcantly.. INTODUCTION Heat lad f a buldng s dependent n the buldng s structure, ts nsulatn and ts characterstcs, vlume, and lcal clmate. Fllwng the reference frm the Chna Heatng Desgn Handbk (Tang and Fan,99), the desgn heat lad per unt area f 6-70 W/m n typcal resdental buldngs can be used t estmate the heatng lad. The methd f the buldng standards has t be fllwed t btan the desgn heat lad.. Buldng Heat Lad Buldng heat lad cnssts f fllwng cmpnents:. Heat lss thrugh buldng envelpe;. Heat lss by nfltratn;. Heat lad f nrush ar; Fgure : Sample buldng n Tanjn The sample resdental buldng eemplfed n ths paper n Tanjn, Chna cntans fur flats f three types. flr layut f the buldng s shwn n Fgure, and the buldng area s presented n Table. Table : reas f the buldng envelpe Type (m ) B (m ) C (m ) Ttal area (m ) f Flr Outer wall Inner wall Wndw CLCULTION OF BUILDING HET LOD The characterstcs f the buldng cnstructn s need t be dentfed t evaluate the buldng parameters, whch are gven by Emesh (00) n Table. The heat transfer ceffcents fr dr and wndws f dfferent s are gven n Table. The fllwng calculatns are based n a steady state energy balance by Chnese and Icelandc buldng cdes fr the sample buldng wth and wthut nsulatn respectvely.. Heat gan by radatn thrugh buldng envelpe. In addtn, ther heat lad factrs, such as llumnatn, human bdy heat and ther addtn heat lad factrs. These are neglected n the heat lad calculatn because they are nsuffcent and unstable. Table Cnstructn s prpertes Cnstructns Densty ρ ((kg/m )) Thermal cnductvty Heat capacty (kj/(kg. Sample Buldng Cncrete Brck Plaster sphalt m f brck Sand Cement tles

2 Le and Valdmarssn Table : Overall heat transfer ceffcents f the dr and wndw Star structure Wndw.70 Steel ( mm ar layer) Wall mm brck Dr.50 Cmpund nsulatn Balcny dr.50. Heat Lss Calculated (Un-nsulated Buldng) The ttal heat transfer ceffcent s ndspensable t heat lad calculatns. Heat transfer ceffcent, s a cnstant that descrbes the heat transfer between the buldng and ts envrnment due t cnductn, cnvectn and radatn, ttal can be calculated accrdng t Eq. tatal + + tatal... C) ) () Where n, n, ttal, n, are the Heat transfer ceffcent f dfferent cmpnents f buldng, surface area f cmpnents, ttal surface area f the buldng, the thermal resstance f heat transfer, ttal thermal resstance f heat transfer, respectvely... Heat lsses thrugh the buldng envelpe ) Wall heat transfer ceffcent The walls heat transfer ceffcent s gven n Table. Table : Outer wall heat transfer ceffcent Outer wall Cnstructn.Cncrete Brck Plaster sphalt Cncrete enfrced cncrete f brck Plaster e Table 6: f heat transfer ceffcent wthut brck 5 f Cnstructn.sphalt Cncrete cncrete Plaster e / / / / rf.8 ttal )Flr heat transfer ceffcent e / / wall Flr heat transfer ceffcent s gven n Table 7. Table 7: Flr heat transfer ceffcent Flr Cnstructn ) f heat transfer ceffcent The cnstructn s cnsst f cncrete and rf brcks, cncrete. Tw dfferent heat transfer ceffcents need t be calculated. The results are shwn n Table 5 and 6. Table 5: f heat transfer ceffcent usng wth brck f Cnstructn.Tles Cncrete Sand e 0.09

3 Le and Valdmarssn 0.5 / / 0.5. flr ) Wndws The type cmmnly used n Tanjn s sngle glazng wth a value f 6.0 W/(m C). 5) Heat lss n the unheated star area The stars f the buldng are nt heated. The equlbrum temperature n the star area has thus t be calculated. Heat flw frm the heated areas f the buldng nt the star area s equal t the heat lst. Calculatn f the stars temperature s, accrdng t Eq., based n energy balance and the area f each element (Table 8). Tstar ) ( Tstar T ) () Table 8: Star heat transfer ceffcent (m ) Inner wall 9.0. Outer wall 9.0. Dr n nner wall..50 Wndw n uter wall..70 Eq. gves T C star Heat lss frm the stars s then. 9 (W).. Buldng ttal heat transfer ceffcent On the bass f the abve calculatn, the ttal heat transfer ceffcent f a buldng can be summarzed as n Table 9. Table 9:Heat transfer ceffcent f a sample buldng s (m ) f Flr Outer wall Wndw Dr Ttal.8 ( T T ) (W).. Heat lss by nfltratn Infltratn s the leakage f utsde ar nt the huse thrugh cracks arund the wndws and drs, whch depends manly n the tghtness f wndws and drs, as well as the wnd velcty (the pressure dfference between the utsde and nsde f the envelpe). The ar change methd s used here t estmate the vlume f flw f nfltratn ar nt the heatng area, whch s based n the ar vlume n a space beng replaced by utsde ar a certan tmes per hur. Chnese buldng cdes recmmend ar changes per hur fr resdental buldngs, 0.8 s used n Eq. (He and Sun, 99): 0.78n V c ρ ( T T ) (W) () k n p w Where c p, n, V n, ρ d are the specfc heat f ar, ar change rate, rm vlume, arflw rate, ar densty when temperature s T,, respectvely. Usng ar change methd t determne V (m /h), gves: V nv h (m /h) () Where n, V h are the ar change rate, rm vlume, respectvely. Frm Eq (W).. ddtnal heat due t buldng drectn 0. (W)..5 Ttal heat lad (W) ttal t s. Heat Lss Calculated by Chnese Cdes (Unnsulated Buldng).. Heat lsses thrugh the buldng envelpe s fr state heat transfer, the frmula has been gven as fllws: ( T T ) (W) (5) Where,,, T, T are the heat lss thrugh buldng envelpe, heat transfer ceffcent thrugh buldng envelpe areas f buldng envelpe, ndr temperature, utdr temperature, respectvely. Table 0: Heat transfer ceffcent f buldng envelpe C) ) (m ) f Flr Outer wall Wndw Star Dr Ttal 87.6 T ) 5.6 (W)

4 Le and Valdmarssn.. Infltratn Frm Eq., 8. 5 (W).. Heat lad f nrush ar due t penng the drs and wndws Heat lss f eternal dr s.8 W, S addtnal heat lad f nrush ar s: 65N%.8.0 Where N s the number f stres.. ddtnal heat due t buldng drectn..5 Ttal heat lad 0.6 (W) (W) (W) ttal t s. Buldng Calculatn (wth nsulatn) by Icelandc cdes.. Heat lad f buldng envelpe (Iceland standards UDC ) ) Wall heat transfer ceffcent The uter wall heat transfer ceffcent s gven n Table. Table : Outer wall heat transfer ceffcent Outer wall Cnstructn.Plaster Cncrete Insulatn e 0.7. / /. 0. rf ) Flr heat transfer ceffcent The ttal heat transfer ceffcent f the flr s gven n Table. Table : Flr heat transfer ceffcent Flr Cnstructn.Flr layer Cncrete Insulatn j / / flr Heat transfer ceffcent f buldng envelpe s summarzed n Table. ccrdngly, Heat lad f buldng envelpe s calculated. Table : Heat transfer ceffcent f buldng envelpe. Plaster C) ) (m ) + e / / wall ) f heat transfer ceffcent The heat transfer ceffcent f the rf s gven n Table. Table : f heat transfer ceffcent f Flr Outer wall Wndw Star Dr Ttal 79.8 f Cnstructn.Wden panel 0.0. ck Wl Wd 0.. Plankng T ).7 (W).. Infltratn Frm Eq., 8. 5 (W).. Heat lad f nrush ar due t drectn Frm Eq. 5, 0. (W)

5 Le and Valdmarssn.. ddtnal heat lad due t buldng heght 7.95 (W)..5 Ttal heat lad ttal + t + + s.68 (W). Buldng Calculatn (wth Insulatn) by Chnese Cdes (Zhang and Zhu, 00) The fllwng calculatns are accrdng t Chna cdes and gven fr cmparsn... Heat lad f buldng envelpe ) Wall heat transfer ceffcent The wall ttal transfer ceffcent s gven n Table 5. Table 5: Outer wall heat transfer ceffcent Outer wall Cnstructn.lme mrtar α (m C Cncrete Insulatn Tle e 0.0. / /. 0.6 wall 7.Plaster e / / rf ) Flr heat transfer ceffcent The ttal heat transfer ceffcent f the flr s gven n Table 7. Table 7: Flr heat transfer ceffcent Flr Cnstructn α.tle Cncrete Insulatn Lme & sl mture / /. 0. flr The heat transfer ceffcent f the buldng envelpe s summarzed n Table 8. ccrdngly, heat lad f the buldng envelpe s calculated. Table 8: Heat transfer ceffcent f buldng envelpe ) f heat transfer ceffcent Table 6: f heat transfer ceffcent. C) ) (m ) f Cnstructn α f Flr Outer wall Cement mrtar.waterprf Wndw Star Dr Ttal 86..Same as Plaster Insulatn cncrete T ) 5.00 (W).. Infltratn Frm Eq., 8.5 (W) 5

6 Le and Valdmarssn.. Heat lad f nrush ar Frm Eq. 5,. 0 (W).. ddtnal heat lad due t buldng drectn 0.6 (W)..5 Ttal heat lad (W) ttal s. CONCLUSIONS Tab. 9 shws the cmparsn f buldng calculatn wth and wthut nsulatn by Chna and Iceland cdes. Table 9: Cmparsn f heat lad calculatn fr sample buldng Heat lad (W) Wthut nsulatn Iceland cdes Chna cdes Wth nsulatn Iceland cdes Chna cdes Thermal nsulatn s ne f the mst effectve energycnservatn measures n buldngs. ccrdng t cmparsn f heat lad calculatns, the fllwng cnclusns fr a sample buldng n Tanjn are btaned. ) Heat lad s calculated by Icelandc and Chnese buldng cdes, the results f frmer s bgger than that f latter are smlar. ) The results f heat lad calculatns ndcate that thermal nsulatn s an effectve way t reduce energy cnsumptn. Heat lad decreases 5.% when nsulatn s added t the buldng envelpe. ) When the thermal nsulatn prperty s mprved t Icelandc standard, the heat lad decreases t 70.%. Ths s a better way t mprve the thermal nsulatn prperty f the buldng envelpe fr energy savng. CNOWLEDGMENTS I wuld lke t thank the Unted Natns Unversty fr supprtng me durng my study n Iceland. My specal thanks t my supervsr, Prfessr Pall Valdmarssn fr hs great knwledge, patent gudance and help. EFEENCES Tang Hufen and Fan Jan: Heatng system handbk, Tanjn Scence & Technlgy Press, Chna (99). Emesh, M.E.: Smulatn f heatng systems n Jrdanan buldngs, M.Sc. thess, Iceland, (00). He png and Sun Gang: Heatng system, Chna rchtecture & Buldng Press, Chna (99). Thermal nsulatn, Iceland standards UDC , Iceland (975). Zhang esng and Zhu Lvjun: UDC GB , Cde fr desgn f heatng ventlatn and ar cndtnng, Bejng: Mnstry f Cnstructn Chna (00). JGJ6-95, Desgn cdes f energy savng fr resdental buldng, Chna rchtecture & Buldng Press, Bejng, Chna (996). 6